Specific classes of long chain fatty acids have been implicating in promoting various diseases including obesity, metabolic syndrome, diabetes, and cardiovascular disease. Additionally, there is a strong correlation between dietary intake of saturated and trans-unsaturated fatty acids with certain cancers including especially, colorectal and breast. The focus of the present work is to devise high throughput methods to identify compounds that selectively inhibit fatty acid uptake into cells. This proposal specifically addresses goals targeted by program announcement number PA-04-068 to develop assays for high throughput drug screening. Fatty acid uptake is a protein-mediated event requiring a fatty acid transport protein (FATP) and an acyl-CoA synthetase (ACSL). Our laboratory has identified and extensively characterized yeast strains deficient in this uptake system. The transport defect of yeast is complemented by mammalian orthologs of the yeast genes and the mammalian transport system reconstituted in yeast is the target for the proposed automated inhibitor screening method development. The specific aims of the proposal are to: [1] demonstrate the sensitivity and specificity of the mammalian transport proteins expressed in the yeast live cell system for analysis in a 96-well high throughput format; [2] to conduct a proof or principle screen of a diversified small molecule library for compounds that inhibit fatty acid uptake; and [3] to devise secondary screens which employ human cells in culture. Our ultimate goal is to identify compounds that inhibit fatty acid uptake into cells without cytotoxic effects. Such compounds are expected to be useful to prevent intestinal absorption of dietary lipid and/or uptake into other cell types to prevent cell damage caused by excessive concentrations of fatty acids, which lead to disease.